Issue 3823 - Adapt message names used by "Block element" feature for consistency

background.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 36 matching lines @@
 // See http://crbug.com/68705.
 var noStyleRulesHosts = ["mail.google.com", "mail.yahoo.com", "www.google.com"];
 
 var htmlPages = new ext.PageMap();
 
 var contextMenuItem = {
   title: ext.i18n.getMessage("block_element"),
   contexts: ["image", "video", "audio"],
   onclick: function(page)
   {
-    page.sendMessage({type: "blockelement-context-menu-clicked"});
+    page.sendMessage({type: "composer.content.contextMenuClicked"});
   }
 };
 
 // Adds or removes browser action icon according to options.
 function refreshIconAndContextMenu(page)
 {
   var whitelisted = !!checkWhitelisted(page);
   updateIcon(page, whitelisted);
 
   // show or hide the context menu entry dependent on whether
@@ skipping 140 matching lines @@
     msg.payload.sender = sender.page.id;
     if (msg.expectsResponse)
       return new Promise(targetPage.sendMessage.bind(targetPage, msg.payload));
     targetPage.sendMessage(msg.payload);
   }
 });
 
 // update icon when page changes location
 ext.pages.onLoading.addListener(function(page)
 {
-  page.sendMessage({type: "blockelement-finished"});
+  page.sendMessage({type: "composer.content.finished"});
   refreshIconAndContextMenu(page);
   showNextNotificationForUrl(page.url);
 });